<?php
require_lib('plugins/barcode/Barcode',false);

class Code39 extends Barcode {
	protected $starting, $ending;
	protected $checksum;

	/**
	 * Constructor.
	 */
	public function __construct() {
		parent::__construct();

		$this->starting = $this->ending = 43;
		$this->keys = array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '-', '.', ' ', '$', '/', '+', '%', '*');
		$this->code = array(	// 0 added to add an extra space
			'0001101000',	/* 0 */
			'1001000010',	/* 1 */
			'0011000010',	/* 2 */
			'1011000000',	/* 3 */
			'0001100010',	/* 4 */
			'1001100000',	/* 5 */
			'0011100000',	/* 6 */
			'0001001010',	/* 7 */
			'1001001000',	/* 8 */
			'0011001000',	/* 9 */
			'1000010010',	/* A */
			'0010010010',	/* B */
			'1010010000',	/* C */
			'0000110010',	/* D */
			'1000110000',	/* E */
			'0010110000',	/* F */
			'0000011010',	/* G */
			'1000011000',	/* H */
			'0010011000',	/* I */
			'0000111000',	/* J */
			'1000000110',	/* K */
			'0010000110',	/* L */
			'1010000100',	/* M */
			'0000100110',	/* N */
			'1000100100',	/* O */
			'0010100100',	/* P */
			'0000001110',	/* Q */
			'1000001100',	/* R */
			'0010001100',	/* S */
			'0000101100',	/* T */
			'1100000010',	/* U */
			'0110000010',	/* V */
			'1110000000',	/* W */
			'0100100010',	/* X */
			'1100100000',	/* Y */
			'0110100000',	/* Z */
			'0100001010',	/* - */
			'1100001000',	/* . */
			'0110001000',	/*   */
			'0101010000',	/* $ */
			'0101000100',	/* / */
			'0100010100',	/* + */
			'0001010100',	/* % */
			'0100101000'	/* * */
		);

		$this->setChecksum(false);
	}

	/**
	 * Sets if we display the checksum.
	 *
	 * @param bool $checksum
	 */
	public function setChecksum($checksum) {
		$this->checksum = (bool)$checksum;
	}

	/**
	 * Parses the text before displaying it.
	 *
	 * @param mixed $text
	 */
	public function parse($text) {
		parent::parse(strtoupper($text));	// Only Capital Letters are Allowed
	}

	/**
	 * Draws the barcode.
	 *
	 * @param resource $im
	 */
	public function draw($im) {
		// Starting *
		$this->drawChar($im, $this->code[$this->starting], true);
		
		// Chars
		$c =  strlen($this->text);
		for ($i = 0; $i < $c; $i++) {
			$this->drawChar($im, $this->findCode($this->text[$i]), true);
		}

		// Checksum (rarely used)
		if ($this->checksum === true) {
			$this->calculateChecksum();
			$this->drawChar($im, $this->code[$this->checksumValue % 43], true);
		}

		// Ending *
		$this->drawChar($im, $this->code[$this->ending], true);
		$this->drawText($im, 0, 0, $this->positionX, $this->thickness);
	}

	/**
	 * Returns the maximal size of a barcode.
	 *
	 * @param int $w
	 * @param int $h
	 * @return int[]
	 */
	public function getDimension($w, $h) {
		$textlength = 13 * strlen($this->text);
		$startlength = 13;
		$checksumlength = 0;
		if ($this->checksum === true) {
			$checksumlength = 13;
		}

		$endlength = 13;

		$w += $startlength + $textlength + $checksumlength + $endlength;
		$h += $this->thickness;
		return parent::getDimension($w, $h);
	}

	/**
	 * Validates the input.
	 */
	protected function validate() {
		$c = strlen($this->text);
		if ($c === 0) {
			throw new BarcodeException('code39 No data has been entered.');
		}

		// Checking if all chars are allowed
		for ($i = 0; $i < $c; $i++) {
			if (array_search($this->text[$i], $this->keys) === false) {
				throw new BarcodeException('code39 The character \'' . $this->text[$i] . '\' is not allowed.');
			}
		}
		
		if (strpos($this->text, '*') !== false) {
			throw new BarcodeException('code39 The character \'*\' is not allowed.');
		}

		parent::validate();
	}

	/**
	 * Overloaded method to calculate checksum.
	 */
	protected function calculateChecksum() {
		$this->checksumValue = 0;
		$c = strlen($this->text);
		for ($i = 0; $i < $c; $i++) {
			$this->checksumValue += $this->findIndex($this->text[$i]);
		}

		$this->checksumValue = $this->checksumValue % 43;
	}

	/**
	 * Overloaded method to display the checksum.
	 */
	protected function processChecksum() {
		if ($this->checksumValue === false) { // Calculate the checksum only once
			$this->calculateChecksum();
		}

		if ($this->checksumValue !== false) {
			return $this->keys[$this->checksumValue];
		}

		return false;
	}
}
?>